Structure for moving an article in the evacuated interior of a corpuscular ray device



March 3, 1970 F. STOCKLEIN STRUCTURE FOR MOVING AN ARTICLE IN THE EVACUATED INTERIOR 3 Sheets-Sheet 1 Filed July 2'7, 1967 \M K L V r w r A u h I I J.\\ v L N om mm Nm D Q ow Q 5 mm QQN mw 51 Inventor:

March 3, 1970 F. STOCKLEIN 3,499,140 STRUCTURE FOR MOVING AN ARTICLE IN THE EVACUATED INTERIOR OF A CORPUSGULAR RAY DEVICE 3 Sheets-Sheet 2 Filed July 27. 1967 D mm 3 mm mwmQQ mm Inventor March 3, 1970 F. STOCKLEIN 3,499,140

STRUCTURE FDR MOVING AN ARTICLE IN THE EVAQU-ATED INTERIOR OF A CORPUSCULAR RAY DEVICE Filed July 27, 1967 3 Sheets-Sheet 5 Fig.3

Inventor:

United States Patent US. Cl. 250-495 Claims ABSTRACT OF THE DISCLOSURE A corpuscular ray device with a hollow evacuated interior in which is situated an article which must be moved. An elongated rod means has an inner end which carries this article and which is situated within the evacuated interior of the device, this rod means having an outer end situated outwardly beyond the evacuated interior of the device, and the elongated rod means has a predetermined axis. A support means supports the rod means for movement not only axially along its predetermined axis but also for turning movement about a second axis which is perpendicular to the predetermined axis. Between this second axis and the outer end there is an elastically deformable means which forms part of the rod means and which lends to the latter the capability of resiliently yielding in a direction perpendicularly to its predetermined axis. A first adjusting means is operatively connected with the outer end of the rod means to adjust the latter axially along its predetermined axis, and a second adjusting means coacts with the rod means for turning the latter about the second axis, so that in this way an article carried by the inner end of the rod means can be moved in the interior of the corpuscular ray device in a pair of essentially mutually perpendicular directions.

My invention relates to structure for moving parts which are situated within the evacuated interior .of a corpuscular ray device.

Thus, my invention relates to a structure which may be used, for example, to adjust a diaphragm in the interior of a corpuscular ray device such as an electron microscope, so that it is possible to move the diaphragm transversely with respect to an electron ray. However, my invention can also be used with advantage with other types of corpuscular ray devices, such as diffraction devices, devices for microanalysis, and ion microscopes, which also have hollow evacuated interiors. Furthermore, beside being used for adjusting diaphragms, the structure of my invention can also be used for moving, in general, relatively light components transversely with respect to the corpuscular ray, such as, for example, specimens, individual pole shoes of an electromagnetic pole shoe lens, or the like.

There are known structures of the above general type such as that disclosed in German Patent 1,018,563, which include an adjusting rod which extends in a vacuumtight manner through the wall of the electron microscope into the evacuated interior thereof where an inner end of the adjusting rod carries a diaphragm, While the rod has an outer end situated at the exterior of the corpuscular ray device and acted upon by suitable threads, for example, so as to bring about axial movement of the adjusting rod and thus movement of the article carried thereby in the interior of the corpuscular ray device. In addition, this structure has a second adjusting means for moving the diaphragm in a direction extending perpendicularly with respect to the electron ray and the axis of the adjusting rod.

With this known construction which has a pair of adjusting structures both of which are required to pass through the wall of the corpuscular ray device to the interior thereof at different locations of this wall, it is essential to provide a pair of vacuum-tight structures for supporting and guiding the pair of adjusting structures at the locations where they pass through the wall of the device into the interior thereof. Furthermore, it is frequently desired, in order to simplify the operations, to locate the drives for moving a given article at a single location, and this highly desirable feature is not met by the knOWn structures.

It is accordingly a primary object of my invention to provide a structure which will avoid the above drawbacks, my invention relating, as pointed out above, primarily to structure for moving articles in the evacuated interior of a corpuscular ray device.

More specifically, it is an object .of my invention to provide a structure of the above general type which will require only a single vacuum-tight passage for the structure through the Wall of the corpuscular ray device.

In addition, it is an object of my invention to provide for the adjusting of an article in the interior of the device, a pair of adjusting means which are situated at a single location at the exterior of the device.

Furthermore, it is an object of my invention to provide a structure which will achieve the latter objects without sacrificing the advantages which are achieved by a pair of distinct adjusting means independently acting to bring about mutually perpendicular movements of the article which is in the interior of the corpuscular ray device.

Thus, in accordance with my invention there is an elongated rod means which has a predetermined axis and which has an inner end situated in the evacuated interior of the corpuscular ray device and carrying the article which is to be moved. This rod means has an outer end at the exterior of the corpuscular ray device, and a first adjusting means is operatively connected with, this outer end of the rod means for axially adjusting the latter along its predetermined axis. A support means is provided to support the rod means not only for axial movement along its predetermined axis but also for turning movement about a second axis which extends perpendicularly across the predetermined axis, and a second adjusting means coacts completely outside said evacuated interior with the rod means for turning the latter about this second axis, the rod means having, as a part thereof, an elastic deformable portion situated between the second axis and the outer end of the rod means and rendering the rod means deformable in a direction transverse to its predetermined axis.

There are known structures Where an object chamber is provided with an object stage as well as with a device which makes it possible to carry out transverse shifting, axial movement, and stereo-tilting of the object. With this construction there is a beam which engages a ball member within the evacuated interior of the microscope and which is supported in a position extending through the wall of the housing of the microscope, while being operatively connected at the exterior of the device with a relatively complex lever assembly turnable in a number of different directions and including a number of springs. Instead of this type of complex construction, the apparatus of my invention requires an exceedingly simple structure for converting rotary movement of a first adjusting means into axial movement of the rod means along its predetermined axis, while the second adjusting means which brings about swinging movement of the rod means about the second axis relies primarily upon the axial movement of a plunger, and in order to adapt the rod means which in any event is required for the first adjusting means to the construction of the second adjusting means it is only necessary to provide the rod means of my invention with the elastic deformable structure which renders the rod means transversely deformable.

My invention is illustrated by way of example in the accompanying drawings which form part of this application and in which:

FIG. 1 is an elongated sectional elevation of one possible embodiment of a structure of my invention, the section of FIG. 1 being taken in a vertical plane which contains the axis of the rod means, and a Wall portion of the housing of the corpuscular ray device is indicated fragmentarily in phantom line in FIG. 1;

FIG. 2 is a sectional plan view, taken in a plane perpendicular to that of FIG. 1, and showing the structure of FIG. 1 also in a plane which contains the axis of the rod means; and

FIG. 3 is again a vertical section of the structure of my invention, the section of FIG. 3 being taken in a plane which extends transversely across the axis of the rod means and which contains the axis of the plunger of the second adjusting means.

Thus, referring to FIG. 1, part of the wall of the corpuscular ray device, an electron microscope in the illustrated example, is shown in dot-dash lines in FIG. 1. In a suitable opening of this wall is located a sealing ring 1 which provides for the vacuum-tight passage of an elongated rod means 2 of my invention through the opening of the housing of the device. In the illustrated example this elongated rod means 2 carries at its inner end, which is shown at the left in FIGS. 1 and 2, a diaphragm carrier 3 which carries a diaphragm in the form of a member provided, for example, with openings of different sizes which can be selectively positioned at the optical axis. Thus, in a manner which is of no particular interest with respect to the present invention, it is possible to mount on the carrier 3 an aperture diaphragm for the objective lens assembly.

As is apparent from FIG. 2, a pair of adjusting means are provided for adjusting the rod means 2, and the first adjusting means 4 is operatively connected with an outer end of the rod means 2 while the second adjusting means 5 coacts with the rod means 2 in a manner described in greater detail below.

Considering first the adjusting means 4 and its operation, this adjusting means 4 serves to achieve an adjustable movement of the rod means 2 along its axis 6. At its outer end where the adjusting means 4 i located, the rod means 2 is provided with an outer thread 7 which is received in the inner thread of an inner sleeve 8 of the adjusting means 4, this inner sleeve 8 being situated within and fixed to an outer sleeve 9 which is provided with an exterior thread of a pitch different from that of the inner sleeve 8 and the thread 7. This outer sleeve 9 of the threaded sleeve assembly, because it has a thread different from that of the sleeve 8 will provide axial displacement of the rod means 2 when both of the sleeves 8 and 9 are turned as a unit, the extent of axial displacement of the rod means 2 being determined by the difference between the pitches of the threads of the sleeves 8 and 9. The outer thread of the outer sleeve 9 coacts with the inner thread of a stationary component 14} of the adjusting means. The illustrated adjusting means 4 is manually operable, and for this purpose it is provided with an exterior knob 11 which is accessible to the operator and which is fixed by a screw 12 with a flange 0f the outer threaded sleeve 9, while the sleeve 9 is in turn fixed by a screw 13 with an exterior sleeve 14 of the adjusting means 4.

By loosening the screw 12 it is possible to turn the sleeves 8 and 9 One with respect to the other by inserting the tip of a screw driver, for example, in the slot 15 at the outer end of the inner sleeve 8, so as to provide in this way a predetermined zeroed position for the rod means 2 with respect to the turning angle of the knob 11 and sleeve 14. In this way the axial position of the rod means 2 can be accurately indicated by a scale carried either by the component 14 or by the component 16.

Through suitable intermediate components, the adjusting means 4 is held by the outer end 17 of a stationary exterior tube 18 which forms part of the support means for the rod means 2 and which is itself fixed t0 the wall of the housing of the electron microscope by way of a threaded ring 19 indicated in FIGS. 1 and 2. In order to guide the rod means 2, the support means includes within the exterior stationary tube 18 thereof an inner sleeve 2b which has an inner end closely surrounding the rod means 2 and which has an elongated sleeve portion 21 extending outwardly from its inner end and surrounding the rod means 2 with clearance. The purpose of the outwardly extending elongated sleeve portion 21 is described below. The rod means 2 extends through the opening 22 formed at the inner end of the sleeve 20, and in order to reduce the friction encountered by the rod means 2 during adjustment thereof, a guide means which includes a roller 23 is provided. This roller 23 is turnably connected directly to the rod means 2, at an elongated inner portion 25 thereof, and this roller coacts with a further roller 52 of the guide means which is resiliently pressed into engagement with a stationary rolling surface 51. As is apparent from FIG. 2, the second roller 52 of the guide means is turnably carried by a tubular component which is fixed to the inner end of the rod means 2 at the interior of the corpuscular ray device and which directly carries the carrier 3 for the diaphragm.

By turning the knob 11, the threaded components of the adjusting means 4 act on the rod means 2 in order to axially displace the latter along its predetermined axis 6, a cross pin 24 being fixedly carried by the rod means 2 at the region of its outer end and extending into axial slots of a stationary member so as to prevent turning of the rod means 2 itself (FIG. 1). Thus, in order to bring about movement of the article acted upon by the structure of my invention transversely with respect to the ray path, this article being the diaphragm holder 3 of the illustrated example, in a direction perpendicular to the direction which extends along the predetermined axis 6, the second adjusting means 5 is provided, this second adjusting means 5 of my invention coacting with the sleeve portion 21, and the rod means 2 being provided with a predetermined construction for this purpose. Thus, the rod means 2 includes, as a part thereof, an elastic deformable means rendering the rod means 2 deformable transversely to its axis 6, and in the illustrated example this deformable means includes three successive rod portions 25, 26 and 27 of which the first inner portion 25 carries the diaphragm holder 3 while the outer rod portion 27 coacts with the adjusting means 4. As may be seen from FIG. 1, the inner rod portion 25 is supported by the support means which includes the sleeve 20 for turning'rnovement about a second axis 30 which extends perpendicularly across the axis 6. This second axis 30 is determined by a pivot means which includes the coaxial pivot pins 28 and 29 fixed to the inner end of the sleeve 20 and received in coaxial openings formed in the stationary tube 18.

The three successive rod portions 25, 26 and 27 are pivotally connected one to the next by means of pivot pins 31 and 32, so that these rod portions are turnable one with respect to the other, and the adjusting means 5 brings about the turning of the rod means about the axis 30 by way of a plunger 35 of the adjusting means 5, this plunger 35 being axially displaceable, having an axis which extends perpendicularly across the axis 6, and terminating at its inner end in a ball 33 which engages a hardened plate 34 fixedly carried by the elongated sleeve portion 21 at the exterior thereof. Thus, when the plunger 35 of the adjusting means 5 is axially displaced, the sleeve together with the rod portion 25 of the rod means 2 will swing about the axis 30. This movement will bring about the desired movement of the diaphragm holder 3 along a circle whose center is in the axis 30, but in view of the required small extent of movement of the diaphragm holder 3, this movement can be considered as extending perpendicularly with respect to the movement brought about by way of the first adjusting means 4.

As is particularly apparent from FIG. 1, the intermediate or second of the series of three rod portions 25, 26, 27, namely the rod portion 26, has a relatively fiat profile. The ends of this second or intermediate rod portion 26 are received in adjoining slotted ends of the rod portions 25 and 27, respectively. These ends of the first and third rod portions 25 and 27 which are directed toward each other and which are suitable slotted to receive the opposed ends of the intermediate or second rod portion 26 carry pivot pins 31 and 32 which extend through openings formed at the end portions of the rod portion 26, so that in this way the successive rod portions 26-27 are pivotally connected one to the next for turning movement with respect to each other in a plane which contains the predetermined axis 6 as Well as the axis of the plunger 35 of the second adjusting means 5. An elastic deformable means is operatively connected with and forms part of the rod means 2, and this elastic deformable means is situated between the turning axis and the first adjusting means 4 and is formed in part by the rod portions 25-27 where they are pivotally connected to each other. In order to render ineffective any play at the pivots 31 and 32, the elastic deformable means includes a compression spring 36 which is coiled about the rod portions 25 and 26 between the inner end of a tube 37 which is fixed to and extends within the sleeve portion 21 and a stop collar 38 which is fixed to the outer end of the rod portion 25. This compression spring 36 of the elastic deformable means thus tends to stretch the rod means 2 in combination with spring 39, and it is apparent that the elastic deformable means formed by this structure renders the rod means 2 deformable in a direction transversely of its predetermined axis 6. In addition, the spring 36 acts as a return spring for the adjusting means 4.

Referring now to FIG. 2, it will be seen that a spring means 39, in the form of a further compression spring, acts on the elongated sleeve portion 21 at a side of the latter which is opposed to the side thereof against which the plunger 33, acts. As may be seen from FIG. 2, the return spring 39 is situated within a suitable fitting carried by a ring 40 which surrounds the tube 18 (FIG. 3), the second adjusting means 5 being fixed to this ring 40. The construction of the second adjusting means 5 corresponds to that of the first adjusting means 4. Thus, in the case of the second adjusting means 5 there is also a knob 41 accessible to the operator and fixed to the assembly of the internally threaded inner sleeve 42 and externally threaded exterior sleeve 43 which are respectively provided with threads of diiferent pitch so that the extent to which the plunger 35 is displaced is determined by the difierence between the pitches of these threads. Thus, the plunger 35 coacts at its outer thread 44, situated at the outer end 46 of the plunger 35, with the inner thread of the inner sleeve 42. A cross pin extends through and is carried by the plunger 35 and has its ends situated in axially extending slots of a stationary component of the adjusting means 5,, so that the plunger 35 together with the ball 33 can only move axially and cannot turn about its axis. Thus, with this construction the actuation of the second adjusting means 5 so as to displace its plunger 35, in cooperation with the action of the spring means 39, serves to determine the angular turning of the diaphragm carrier 3 about the axis 30.

The first adjusting means 4 and the second adjusting means 5 respectively include the detent leaf springs 48 and 49 which respectively form parts of click-stop assemblies which are calibrated in micrometers.

An additional manually-engageable sleeve 50 surrounds and is axially slidable with respect to the tubular component 16 situated outwardly of the tube 18 for selecting the particular diaphragm which is to be placed into the operating position as well as for displacing all of the diaphragms away from the ray path. As may be seen fro-m FIG. 1, the sleeve 50 is operatively connected with a slide ring 53 formed with a slot receiving a suitable pin, so that the required axial shifting of the diaphragm assembly, by relatively large increments, can be brought about by way of the sleeve 50. The diaphragm takes the form, for example, of a plate formed with a plurality of openings of difierent sizes arranged along the axis 6 and spaced by predetermined distance from each other, so that a selected one of these openings or apertures can be situated in the region of the optical axis.

While it is possible for the second adjusting means 5 to act directly on the rod means 2, the illustrated preferred construction of my invention provides an indirect transmission from the adjusting means 5 to the rod means 2 through the sleeve structure 20, 21 inasmuch as the plunger of the second adjusting means 5 exerts a turning moment on the sleeve 20, 21 so as to turn the latter and the rod portion 25 about the axis 30.

In order to maintain a relatively small extent of movement for the plunger 35 of the second adjus ing means 5 while at the same time achieving a substantially large extent of freedom in the choice of the transmission ratio between the movement of the plunger and the movement of the carrier 3 transversely with respect to the corpuscular ray, the sleeve assembly 20, 21 is provided with the relatively long outwardly extending sleeve portion 21 which surrounds the rod means 2 with play or clearance and on which the plunger acts in cooperation with the spring means 39. Thus, it is this elongated sleeve portion 21 which forms the lever arm for the swinging movement of the components about the axis 30 and for transmitting the movement to the rod means 2.

In order to provide the rod means 2 with an elastically deformable region which is transversely deformable, it is possible to use several different constructions. Thus, the required elasticity can be achieved either by a suitable choice of the material for the deformable region of the rod means 2, such as by choosing a suitable springy material, but it is simpler and better to use the construction described above and shown in the drawings. Thus, it is also possible to achieve the transverse deformability of part of the rod means 2 through selection of a suitable material. Of course, the material selected for this purpose should not have any appreciable permanent deformability. However, the above-described structure which is illustrated in the drawings is preferred for this purpose. The intermediate portion 26 of the rod means forms at its pivotal connections to the. first and third portions 25 and 27, respectively, the transversely deformable region of the rod means, while the elasticity of this region is brought about by way of the spring 39. The turnability of the sleeve 20, 21 about the axis 30 brings about the transverse movement without in any way hindering the axial movement of the rod means 2. As was pointed out above, the rod portions 25-27 are turnable one with respect to the next in a plane which contains the axis 6 and the axis of the plunger 35, but in the event that the axis of the plunger 35 does not inersect the axis 6, then the rod portions 25-27 are turnable with respect to each other in a plane which contains the axis 6 and is parallel to, and situated either above or below, the axis of the plunger 35.

The play which may be present at the pivos 31 and 32 may be considered undesirable with respect to the accuracy of the adjustment of the diaphragm or the like transversely with respect to the corpuscular ray as a result of actuation of the first adjusting means 4. This latter factor is alleviated, and avoided, however, by the presence of the compression spring 36 which constantly seeks to pull the rod portions apart from each other. The guiding of the rod means by way of the rollers 23 and 52 not only eliminates frictional resistance to adjustment of the rod means 2 but in addition serves to assure the stretched condition of the rod means resulting from the action of the spring 36. These rollers of the guide means for the rod 2 are respectively situated at opposed sides of the rod means with the one. roller 23 situated within the sleeve 20, 21 while the other roller 52 is situated at the exterior of the sleeve in engagement with the stationary surface 51 within the hollow evacuated interior of the corpuscular ray device.

Thus, it is apparent that the assembly of my invention achieves the pair of adjusting means 4 and without sacrificing the accuracy of the adjustment transversely with respect to the corpuscular ray. This accuracy of the adjustment is achieved in particular by the arrangement of the inner and outer threaded sleeves of each adjusting means, these sleeves having threads of different pitch, as pointed out above. This diiferential threaded arrangement provides an extremely fine adjustment which can be calibrated in micrometer graduations.

The use of a ball member 33 for the inner end of the plunger 35 where it engages the sleeve portion 21 is of particular advantage since in this way there is at all times a precisely proportional transmission of the plunger movement at a predetermined point of engagement with the sleeve portion 21.

It will be noted that the single tube 19 of the support means of my invention provides a supporting structure for both of the adjusting means. As is apparent from FIG. 3 in particular, the tube 18 is formed in its wall with a pair of diametrically opposed openings, and in FIG. 3 it will be seen that through one of these openings the spring 39 acts while through the other of the openings the plunger 35, 33 acts. It is only necessary to disconnect the tube 18 from the corpuscular ray device in order to remove the entire structure of my invention therefrom.

It will furthermore be noted that both of the adjusting means 4 and S are situated in a plane which extends transversely across the corpuscular ray, the arrangement being such that the first adjusting means 4 extends laterally with respect to the operator while the second adjusting means 5 is situated forwardly of the operator.

1 claim:

1. For use with a corpuscular ray device having a hollow evacuated interior, elongated rod means having a predetermined axis and having an inner end situated in the hollow evacuated interior of the device for carry ing an article therein and an opposed outer end situated at the exterior of the corpuscular ray device, support means supporting said elongated rod means for adjustable movement both along said predetermined axis thereof and about a second axis perpendicular to said predetermined axis to the ray, elastically deformable means forming part of said rod means and situated therealong between said second axis "and said outer end thereof, first adjusting means mechanically engaging said outer end of said rod means for adjusting the latter axially along said predetermined axis thereof, and second adjusting means disposed without said evacuated interior and mechanically engaging said rod means for turning the latter about said second axis, so that an article carried by said inner end of said rod means can be adjusted in a pair of mutually perpendicular directions.

2. The combination of claim 1 and wherein said support means includes a sleeve extending coaxially along and surrounding said rod means, and pivot means forming part of said support means and supporting said sleeve for swinging movement about said second axis, said second adjusting means coacting with said sleeve for turning the latter about said second axis and acting through said sleeve on said rod means to adjust the latter with respect to said second axis.

3. The combination of claim 2 and wherein said second adjusting means includes a plunger extending perpendicularly with respect to said predetermined axis and engaging said sleeve to exert a turning moment thereon for turning said sleeve about said second axis.

4. The combination of claim 3 and wherein said plunger engages said sleeve at one side thereof, and spring means coacting with an opposed side of said sleeve for urging the latter toward said plunger.

5. The combination of claim 4 and wherein said sleeve has an inner end portion closely surrounding said rod means and has an elongated sleeve portion extending outwardly from said inner end portion and surrounding said rod means with clearance, said second adjusting means engaging said sleeve portion of said sleeve with said plunger of said second adjusting means.

6. The combination of claim 3 and wherein said rod means has three successive portions pivotally connected one to the next to form part of said elastically deformable means, and said three successive portions of said rod means being turnable one with respect to the other in a plane which contains said predetermined axis of said rod means and the axis of said plunger of said second adjusting means.

7. The combination of claim 6 and wherein said three successive portions of said rod means include first and third portions respectively having slotted ends directed toward each other and a second portion of substantially flat profile received in said slotted ends of said first and third portions and pivotally connected to said first and third portions at said slotted ends thereof, respectively.

8. The combination of claim 7 and wherein said elastically deformable means includes, in addition to said three successive pivotally interconnected portions of said rod means, a spring coacting with said rod means for yieldably opposing slackness between said portion of said rod means.

9. The combination of claim 7 and wherein said elastically deformable means includes a compression spring situated within said sleeve portion between the latter and said rod means, and said compression spring acting on the one hand on said sleeve portion and on the other hand on one of said three successive portions of said rod means which is situated within said sleeve portion for yieldably opposing turning movement of said three successive portions of said rod means one with respect to the other.

10. The combination of claim 6 and wherein a guide means coacts with said one portion of said rod means which is situated in said sleeve portion for guiding said one portion for axial movement along said predetermined axis, said guide means including a roller and a surface having rolling contact with said roller.

11. The combination of claim 1 and wherein said first adjusting means includes a thread at said outer end of said rod means, an inner sleeve having an inner thread engaging said thread at said outer end of said rod means, an outer sleeve surrounding and fixed to said inner sleeve and having an exterior thread which is of a pitch different from the interior thread of said inner sleeve, and an exterior stationary component surrounding and coacting with the threads of said outer sleeve, so that upon turning of said inner and outer sleeves as a unit said rod means will be axially displaced with respect to said stationary component.

12. The combination of claim 1 and wherein said second adjusting means includes an elongated plunger extending perpendicularly with respect to said predetermined axis and coacting with said rod means for turning the latter about said second axis, said plunger having an outer threaded end portion, and said second adjusting means further including an inner sleeve threaded on said outer threaded portion of said plunger, an outer sleeve fixed to said inner sleeve and having an exterior thread of a pitch diiferent from that of said inner sleeve, and an exterior stationary component surrounding and coacting with the threads of said outer sleeve, so that when said outer and inner sleeves turn as a unit said plunger will be axially displaced to adjust said rod means about said second axis.

13. The combination of claim 1 and wherein at least one of said adjusting means includes click-stops calibrated in micrometers.

14. The combination of claim 1 and wherein said sec- 0nd adjusting means includes an elongated plunger ex tending perpendicularly with respect to said predetermined axis for turning said rod means about said second axis during axial displacement of said plunger, and said plunger having an inner end direction toward predetermined axis and carrying a ball.

15. The combination of claim 1 and wherein said support means includes an outer stationary tube mounted on the corpuscular ray device and coaxially surrounding said rod means and said elastically deformable means, said stationary tube having an outer end carrying said first adjusting means and said support means including a ring surrounding said tube and carrying said second adjusting means, said tube being formed with a pair of 0pposed openings passing therethrough, said second adjusting means including a plunger extending through one of the latter openings perpendicularly to said predetermined axis for turning said rod means about said second axis and spring means situated in the other of said openings and acting on said rod means in opposition to said plunger to maintain said rod means coacting with said plunger.

References Cited UNITED STATES PATENTS 2,602,899 7/1952 Page.

ARCHIE R. BORCHELT, Primary Examiner 20 S. C. SHEAR, Assistant Examiner 

